macOS Gatekeeper "damaged" error on unsigned CLI tools

When a freshly downloaded, un-notarized macOS binary reports "is damaged and cannot be opened, move it to Trash", it is almost never real corruption — it is Gatekeeper reacting to the com.apple.quarantine extended attribute. Clear it with xattr -cr <path> (all xattrs, recursive) or xattr -dr com.apple.quarantine <path> for just that flag. Self-contained .NET CLI builds then run directly; only GUI .app variants additionally need a .NET runtime installed.